MONTPELIER — Parents of children with autism were elated Wednesday when Gov. Peter Shumlin signed a bill that will make more Vermonters with developmental disabilities eligible for insurance coverage. (Washington County Senator Anthony Pollina was the lead sponsor of the bill.)

The parents have been the most vocal advocates for the bill, fighting for years to get the legislation passed so their children and others can receive therapy to overcome difficulties stemming from their disability.

“This is the first time I can say a bill will affect my life,” said Angela MacDonald-Timpone, a Montpelier resident and the mother of a 10-year-old with autism. “It’s hard for legislation to do that.”

Sen. Philip Baruth, a Chittenden County Democrat, said the legislation has drawn emotional reactions from Vermonters in his district.

“A few of the bills I’ve worked on here my constituents know about,” said Baruth. “This is the only one where people have actually cried when I’ve told them it’s passed.”

Lawmakers passed a bill in 2010 that required coverage by private insurance companies for children up to age 6.

The new law expands that and requires private insurance companies and Medicaid to pay for therapy for Vermonters 21 and younger with developmental disabilities like autism.

“Unfortunately up until now if you have a family member with autism or a developmental delay, you’ve been shut out,” said Sen. Anthony Pollina, a Washington County Democrat-Progressive.

With the new law, Vermont joins 30 other states with “meaningful” autism insurance reform, according to Judith Ursitti, of the group Autism Speaks.

Vermont is the only state that includes Medicaid in its mandate, said Ursitti.

“Now you have one of the strongest bills in the country,” she said.

The Shumlin administration had intended to continue delaying the Medicaid component of the mandate included in the 2010 law amid concerns about cost. But a review by the Legislature’s Joint Fiscal Office this year found previous projections overstated the financial impact of a Medicaid mandate, which would actually be “minimal” in the short term.

Advocates will now work to make sure the law is properly implemented, said Ursitti.

Children with autism can make great strides if they receive therapy early in life, said MacDonald-Timpone.

“We knew early intervention was key, and we took any money we had and put it into that, and he’s thriving,” MacDonald-Timpone said of her son. “I’m hoping that can happen for all kids, not just my son.”

Shumlin said the new law will go a long way to making that happen.

“We know that early diagnosis and treatment makes a difference, and this bill will ensure that we get the early diagnosis and get treatment and that no parent is sitting there saying, ‘I can’t get the services my child needs because I can’t afford it,’” said Shumlin.